Telautophote.



PATENTED DEC. 24, 1907.

S. ROTHSCHILD.

TELAUTOPHGTE.

APPLIoATIoN Hman s112126, 190e.

5 SHEETS-SHEET 1.

W/TNESSES ATTORNEYS PATENTED DEG. 24, 1907.

5 SHEETS-SHEET 2.

/NVENTOH W/TNESSES SYM@ A TTOHNEYS kNo. 874,868. PATBNTBD DEG. 24, 1907.

s. ROTHSCHILD.

TELAUTOPHOTB.

APPLICATION FILED SEPT. 6, 1906.

5 SHEETS-SHEET 3. Qu l 5 7 @s N No 874,868. PATENTBD DEG. 24, 1907.

8. ROTHSCHILD.

TELAUTOPHOTE.

APPLIUATION FILED SEPT. s, 190e.

SEEETs-SHBBT 4.

'wm/5885s /NVENTOR TTHNEYS PATENTED DEC. 24, 1907.

S. ROTHSCHILD.

TELAUTOPHOTE.

APPLIOATION FILED SEPT. e. 190e.

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m N d Imi A TTU/NVE YS UNITED STATES PATENT oFF-10E.

' SIDNEY no'rnscnILD, or NEW YORK, N.-Y. i

2mm n. 24, 1907.

Anuman 1.a mamar 6.1006. snm Na-ssasza To all whoni 'it may concern:

Be it known that I SIDNEY RoTHscrnLn, a citizen of the United States, and a resident ofthe city of New York, boroughof Man-l hattan, in the county and State of New York, have invented a new and' Improved Telautophote, of which the following is a full, clear, and exact descri tion.

My invention relates to t e transmission of images by electricity, 'my more particular object being to provide for this purpose an efficient a paratus possessing certain constructionalpadvantages hereinafter described, the apparatus using a single wire for connecting together the receiving and sending stations.

Briefly summarized, m invention consists in causinga light-control ed composite background to vary the intensity of electrical `currents flowing over a wire, and causing these currents to control the intensity of a light at the receiving station, this light being caused by approprlate mechanism to produce a moving luminous spot of varying intensity .in such manner as'to reproduce a fac-simile of an image disposed adjacent to the aforesaid background at the transmitting station.

Reference is to be had to the accompan ing drawings formin a part of this speci cation, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a diagram showing the optical and electrical equipment of the s stem, in-l cluding both the transmitting an receiving stations; Fig. 2 is a side elevation of the mechanism used at the sending station, and shows in diagram a part ofthe Wiring; Fig. 3 is an enlarged seetion,' artly diagrammatic, showing the portion o the mechanism employed at the transmitting station, and especially the light-controlled back ound and the light-controlled switch for a ecting the flow of currents relatively to` this background, and also showing in diagram a art ofthe wiring; Fig. 4 is a front elevation o the light-controlled background, the selenium fuse thereof being removed; Fig. 5 is a side elevationof the principal a paratus used at the receiving station an provided with means for projecting upon the screen the image transmitted to this station; Fig.4 6 is a central vertical section through the mechanism shown in Fig. 5, and showing particularly the arrangement of the slotted wheel and slotted belt for controlling'the direction of the light projected for roducin the images; Fig. 7 is a diagram o the synclironizin system and of the electric motors controlle t ereby and located at the sending and receiving stations for the purpose of propelling and maintaining in unison the members wherein' certain parts are located respectively at these stations; Fig. 8 is a erspective view of the selenium cell emp oyed in the light-controlled switch at the sendin station, this cell being made in sections; an Fig. 9 is a fragmenta front elevation of the upper right corner of t e selenium cell shown in Fig. 8 and showing how the sections are assembled.

A number of metallic strips 9, 10, 11, 12, 13 and 14, preferably of tin-foil, copper, brass, platinum, or other metal commonly vused in photophones, are separated from tiguous edges of the strips as will be understood from Fig. 3. -The selenium coating 15 after being applied in a vitreous state is baked and otherwise treated so as to render it sensitive to light in the manner well understood with reference to the preparation of li ht-controlled selenium cells. A pane of ass 16 is connected integrally with the casmg 17 of the same material and serves to protect the selenium coating from the action of the atmosphere.

The selenium cell as a Whole'is shown in Fig. 4 and in the left hand portion of Fig.3. The strips l() to 14 inclusive, and insulating strips 14.l therebetween, are of such thickness that the metallic strips make about one hundred and fifty to the inch. The selenium cell just described is used yas a background for receiving light from the object, the image of which is" to be transmitted.

Another selenium cell is shown in Fig. 8, and is built up of sections 18, 19, 2O and 21, each having a sector-like form and provided upon its o posite ends with tongues 22 for convenient y` mounting it in position. A battery 23 is situated at the transmitting station, and from this battery a Wire 24 is connected with a number of branchin wires 25, 26, 27, arranged in parallel wit each other as will be understood from Fig. 3. Eachl of these wires is connected with a metallic strip, such as 28, forming a part of the of a comparatively narrow bar.

30 and 31 are incorporated in this cell, each consecutive pair of strips such as 28, 29,. or 30, 31, being connected together by a coating 32 of selenium. 'lhis coating has the form All of the metallic strips in this selenium cell are insulated fr'oin each other as will be understood from Fig. 3. VViles 33, 34 are connected with the strips 13, 14. The wire 33 connects with the strip 29 and the wire 34 with the strip 30. Since the stris 30, 31 are aired together and connecte at their faces liy the same coating 32, and since the strips 28, 29 are similarly connected by another coating 32, it follows that the wires 33, 34 connect with dillerent pairs of strips of the selenium cell shown at the right of Fig. 3. The purpose of this4 arrangement is hereinafter explained. Wires 35, 36, 37 and 38 are each connected with the metallic strips 9, 10, 11 and 12 and with a pair of the contact strips in the other selenium cell shown in Fig. 8 and in the middle of Fig. 3. One contact strip in each pair of this cell (for instance the contact strip 31) is connected by a Wire 39, 40 or 41 in parallel with a wire 42 which is connected with a primary winding 43, and this is in communication by a wire 44 with the battery 23. A secondary winding 45 is disposed in inductance relation to the primary winding 43 and is grounded at 46. nected with the secondary winding 45.

The selenium cell shown in Fig. 8 and at the center of Fig. 3 is illuminated over a small portion of its surface at a time by means of a vacuum tube 48 which is provided with a reflector 49. The vacuum tube 48 may be a Geissler tube, a mercury vapor tube, or any other tube through which currents are sent for the purpose of causing a glow to take place. At the transmitting station (see Fig. 2) is a source of electricity 50 for energizing the vacuum tube 48. This source of electricity is conventionally shown as a battery, but may be a dynamo supplying direct or alternating current, or may be any equivalent machine or instrument for generating currents of the character suitable for illuminating the tube 48. Since the pu ose of the vacuum tube 48 is merely to pro uce a light, it is obvious that I do not limit myself to the employment of a vacuum tube for this purpose. A source of electricity 50 is connected with the tube 48 by a wire -51. From this tube a wire 52 leads back to the battery 50. A hand switch -53 may be used for opening and closing the circuit from the battery. A revoluble cylinder 54 is provided with a series of slots 55, 56, 57, 58, each being adapted to register with one of the sections 18, 19 20 and 21 of the selenium cell shown in Fig. 8. The slots 55 to 58 inclusive are staggered relatively to each other and so dispose that only one of them at a The line wire is shown at 47 and is contime is in communication with oneof the sections 18 to 21 inclusive. For instance, when a slot 55 is allowing light to shine upon a section 18 the other sections are all dark, and when the next slot 56 throws light upon the section 19, the said section is the only one receivi any illumination. The slots arc dispose A vertically and are comparatively narrow so as to cxposeonly one pair of coatings 32 of each section at a time, as will be understood from Fig. 3. The revoluble cylinder 54 is supported by a frame '59 and is turned by a shaft 6() provided with a pinion 61 which meshes with a gear whec1'62. The latter is mounted upon a stub shaft 63, carrying a pinion 64, and the latter meshes with a gear wheel 65 of the motor 66. This motor at the transmitting station is synchronized with another motor at the receiving station as hereinafter described.

Revolubly mounted upon a framework 67 is a gear wheel 68 which meshes'with the gear wheel 65. The gear wheel 68 is connected by a stub shaft 69 with a gear wheel 70, and the latter meshes with pinions 71 mounted u on revoluble shafts 72. Carried by these s afts are rollers 73, and running upon these rollers is a comparatively wide belt 74 provided with longitudinal slots 75 disposed crosswise of the belt which travels in the direction indicated by the arrow in Fig. 2. S rocket chains 76 running upon sprocket W eels 77 gear the shafts 72 and the rollers 73 mounted thereupon in such manner as to cause the same to move positively. Each slot 75 is of a length substantlally equal to the height of the selenium cell shown in Fig. 4. A llens 78 or equivalent objective glass is disposed in front ofthe selenium cell 17 and is adapted to throw u on the same a fac-simile of the object, the image of which is to be transmitted, as will be understood from the diagram at the left of Fig. 1.

The line wire 47 is provided with a condenser 79 and connected with this condenser at a point near the receiving station is a wire 80 constituting a continuation of the main line wire. This wire 80 is connected with a rimary winding 81 and with a wire 82. From the last mentioned wire a wire 83 is connected with the Ground at 84. A wire 82l is connected with the wire 80. A secondary winding 85, disposed in inductive relation to the primary Winding 81, is connected by a wire 86 with an electric lamp 87. This electric lamp may be a vacuum tube of the kind above described, or may be a so-called Nernst lamp. A wire 88 connects its u per end with the secondary Windin 85. he wires 82, 82 are connected wit a source of electric current, preferably alternating, so as to light up the lamp 87. If an alternatinfy current is used it should preferably be o? high frequency, but this is not in all cases necessary, for the reason that the glow of the tube does erases not diminish materially .between successive 93 being alternations of the current unless the current be of exceedingly low frequency. The glow from the Vlamp 87 should be normally continuous and constant, or at least practically so, and this result is easily attained. ble wheel 90 is provided with slots 91 and is turned-at a comparatively highl speed by means of bevel gears 92, 93, the bevel gear rigid upon'a revoluble shaft 94. Mounte upon the lower end of this shaft is a inion 95 which meshes with a gear wheel 96.

he latter is mounted upon a' stub shaft 97 carrying a pinion 98, and the latter meshes with a arge gear 99 propelled by a motor 100. A pmion 101 carried by a shaft 102 transmits motion from the gear wheel 99 to a roller 103. A belt 104 engages this roller and is provided with vertically-disposed slots 105. These slots pass overthe face of the wheel 90. Rollers 103 and 103b also engage the belt 104. The rollers 103 and 103 are provided with projections 106 for preventing the belt 104 from slipping and for `enerally maintaining it in a ositive worklng relation to the rollers. lens 108, or equivalent objective, is used for the purpose of definin an ima e upon a screen 109 as will be un erstood rom Fig. 5.

The motor 66 at the transmitting station and the motor 100 at the receiving station are partly electrical and partly mechanical,

ybeing made in accordance with Wellknown principles. These f` motors do not differ essentially from others heretofore in use. Such bein the case, their electrical connections are s own diagrammatically as will be seen from Fig. 7. An electric motor 110 is provided with a revoluble disk 111 enga ing a stationary brush 112 which is connecte by a wire 113 with the round at 114. A battery 115 is connecte by Wires 116,. 117 with the motor 110 for the urpose of turning the revoluble disk 111. brush 118 is in electrical communication with the disk 111, which is of conducting material, preferably metaLand is provided with teeth 119 of the same material and se arated from each other by s aces 120 led with insulating material. eeth of this kind are not apt to spark and' break the electrical connection positively and precisely. A Wire 121 connects the brush 1.18 with a battery 122. The motor 110, battery 115 and battery 122 may be located at any convenient point alono the line. The battery 122 `is connected by a wire 123 with an electro-magnet 124 at the transmitting station. A Wire 125 leads from v this electro-magnet to another electro-magnet 126, which is located at the receiving station and is connected by a wire 127 to thl ground at 128. Vibratory forks 129 are djs posed opposite the magnets 124 and 126^and are adapted to open and closel the contacts 130 and 131 when energized and denergized Connected with each tuning '70 of wires 132 and 136 reprewith a resistance 139 shunted across the brushes 140, 141 of the motors 66 or'100.

When the motor 1 10 causes the disk 111 to rotate the teeth 119 engage and dlsengane the brush 112 and current is sent over t' e synchronizing line shown in Fig. 7, the 01rcuit being as ollowsz-Battery 122,w1re 121, brush 118, disk 111, brush 112, w1re '1 13, ground at 114, ground at 128 of the recelving station, wire 127, electro-magnet 126, wire,l

125 to transmitting station, electro-magnet 124 at the transmitting station, and w1re7123 back to the battery 122. 'lhevforks 129, one located at the receiving station and the other at the transmitting station, are attracted and released by the electro-magnets 126 and are thus caused to vibrate in unison. In vibrating each fork makes and breaks contact with the contact point 130 and also with the contact point 131.

' When the fork 129 is in communication with the contact`130 the course of the current is as follows: Wire 132, resistance 133, wire 134, contact point 130, fork 129, wire 138, noninductive resistance 139, which impedes its direction, thence branching oif through brushes'141, motors 60 and 100', brush. 140, resistance 135 and wire 136 back to the source of ener When v.the ork 129 engages the contact point 131 the circuit is las follows: Wire 132, resistance 133, part of resistance 135, non-1nductivereslstance 139, brush 140, motor 66 or 100, brush 141, wire 138, fork 129, contact point 131, Wire 137, and Wire 136 back to the source of supply. The vibratory forks 129 thus supply current to their respective motors 66 and 100 in such manner that these motors are energized synchronously and thus serve to synchronize the movable parts actuated thereby. Inasmuch as the details of the synchronizing mechanism form no part of my invention I Willnot describe them in detail, but they can be found in any standard Work relating to the general subject of electrical synchronizing.

The speed of the Wheel 90 is ver7 high as compared with the speed of the cy inder 54 and the belt 74. The speed of the belt 74 hould be so high that one ofthe slots 105 moves across the face of the selenium cell 17 shown in Fig. 4 in one-fifth of a second or less. The c linder 54 should be of such speed that one o the slots 55, 56 or 57, 58 passes over the face of a section 18, 19, 20 and 21 in onetwelve-thousandth part of a second. This would correspond tov a speed of twenty-two -thousand five hundred revolutions er minute for the c linder 54 and this wou d represent seven hundred and twent thousand ilashes er minute. It is essentlal that the speed o the cylinder 54 be high as com ared with that of the belt 74'.y It necess follows from the electrical connections s own in Fig. 2 and elsewhere that when'the successive slots 55 56, 57 and 58 travel vsuccessively past t e res ective sections 18, 19, 20 and 21 as above dbscribed, the conducting strips 9, 10, 11, 12, 13 and 14 are all successively energized from top to bottom of the selenium cell shown in Fig. 4. That is to say, strip No. 14 is first energized, then strip No. 13, nextstrip No. 12, and so on down through the entire series, the bottom strip being energized just as one of the slots 58 passes oil the edge of the section 21. This assumes, of course, that the lamp 48 is sending a beam of light through the slots 55, 56

and 57. At the receiving station the speed of the belt 104 is such that the several slots 105 pass any given point during the time interval required for the corresponding number of the slots 75 to pass the given point. The movements of the belts 74 and 104 are synchronized for this purpose. The gearing I at the receivin station 1s so arranged that the slots 91 in t e wheel 90 pass downwardly at a point adjacent tothe lens 108 at a rate of s eed which is related to the rate o speed of t e cylinder 54.

Any number of slots 91 may be made in the Wheel 90, but it is essential that whatever be the number the slots must travel at such a rate of speed that each of them travi erses a distance representedv by the virtual length of the slot 105 during the time interval required for a group of slots 55, 56, 57 and 58 upon the cylinder 54 to pass in succession the respective sections 18, 19, 20 and 21; that is to say, each section 18, 19, 20 and 21 should have each of its selenium coatings illuminated once while the wheel 90 travels far enough to enable one of its slots 91 to pass downwardly a distance represented by the height of a slot 105. 1t 1s obvious, therefore, that the gearing of the several movable parts may be varied considerably, provided It will be understood in this connection '75, but varying su, ses

continues for an instant after the cessation of each current pulsation. This continuous the persistence of vision it may have the ef-` fect of rendering the emission of light from the lamp practically constant under normal conditions.

The action of my device is as follows Suppose that an image re resented by a ieture is to be transmitted). It is laced, in front of the lens 78 as indicated by t e legend ob'ect in Fig.- 1. The image would now be efined upon the face of the selenium cell 17 in much the same manner that it would be defined upon the screen in a camera, exce t for the fact that the selenium cell 17 is or the most part hidden by the belt 74. The entire image is therefore not formed all at the same time u on the selenium cell 17.V Only so much o the image as is represented by the length and the width of a slot 75 makes its appearance at any one moment. The selenium cell is therefore illuminated by a verticalline or beam of light substantially co-incident with a slot in intensit at different points alon its ngth according to the portions of t e image fragmentarily represented by it. Such being the case, the conductivity of the various portions of the selenium coating 15 is varied in this sense that a series of ima 'nary -points located vertically in a line ave their respective ohmic resistances varied by the action of the light upon the selenium coating. At the same time that the vertical beam of light is passing horizontally across the selenium cell 17, the cylinder 54, by its revolution, causes the several slots 55, 56, 57 and 58 to pass the respective sections 18, 19, 20 and 21 as above described, and as the intensity of illumination of the lamp 48 is constant, the several longitudinal coatings 32 o f selenium each receive in succession the same degree of illumination. to controlthe uniform fiow of the electric current, and the revolution of the cylinder 54 relatively to the sections 18, 19, 20 and 21 is analogous to the action of a switch. Suppose, now, that a particular oint upon the coating 15 of the selenium ce l shown in Fig. 4 happens, because of the definition of the image lupon it, to be illuminated by a spot of light, representing, I will say, the light reflected from some luminous point in the image. It is clear that this oint of illumination remains always in t e same position, and that it must e thrown intermittently upon the selenium coating 15 but always occupies the same position thereupon. Let us suppose, for the sake of simplicity, that this point of light falls upon that portion of the selenium coating 15 immediately over the two conducting strips 13, 14. As

ibo

erases a matter of fact, there being-a large number of theseV conducting strips, and they being disposed very close together, almost any spot of livlit or aliiiost anyshadow, however small, will traverse a large number of them.

Indeed for clearness of outline it is essential that all of the conducting strips of the cell 17 be made as thin and -arranged as closely together as possible. for the sake of illustration that above and below the single point of light just referred to the image is of such character as to represent a total lack of li ht. The illustration may, perhaps, be ren ered clearer b supposing that the point of li ht is a sing e star in a portion of t e sky. he rotation vof the lcylinder 54 in causing light to bethrown t rough the slots 55 upon the several coatings 32 is unable to cause any electrical current-to flow through'either of the selenium cells, except when the beam of light through the. slot 55 falls upon the particular coating ,32 coveri the particular strips 29, 30, leading to t e stri 13, 14 u on which the spot of light is fa ling. Un er the conditions just described the following circuit is completed: Battery 23, wire 24, Wire 27,

strips 28, 29 through their` selenium coating,

wire 33, strips 13, 14 through the ortion of the selenium coating 15 covere by the light spot, Wire 34, strips 30, 31 through their selenium coating 32, wire 39, wire 42, primary windin 43, and wire 44 back to the attery 23. momentarily energizes the primary winding 43 and causesl it to act inductively upon the secondary winding 45,

thus sendin a momentary alternating current over the line 47, the intensity of the current varying by the resistance of the circuit just traced and being proportionate to the intensity of the light spot thrown upon the selenium cell 17 Owing to the synchronization of the movable parts at the receiving and transmittin stations, the alternating current controlled by' the light spot passes over the line 47 at the exact instant when the slot 75 of the receiving apparatus occupies a position corresponding to that of the light spot at the transmitting station, this position being reckoned, we will say, from a given edge or corner of the cell 17, and at the same instant when the slot 91 of the relay 90 is in a position representing the position of the light spot upon the cell 17 55 as reckoned, we will say, from another edge or corner of this cell. In other words, the vwertically disposed slot 105 ofthe belt 106 and the horizontally disposed slot 91 of the rela 90 cross each other at a definite point 60 having a spatial relation correspondin to the osition of the li ht spot upon'the cel 17 At t e instant just escribed the light of the lamp 87 necessarily undergoes a. change. Normally this lamp has a definite and constant degree of illumination produced as fol- Let us suppose further lows: An alternating current passes through the wire 82, primary windin 81 and wire 82 back to the source of supp y. This causes the primary winding 81 to act inductively upon the secondarywindi 85, thereby causing the lamp to be illuminated, as will .be readily understood. At the precise instant when the momentary alternatf' current is sent over the line 47 as above escribed, the primary'winding 81, acting under this impulse, energizes the winding 85 inde endently of the suppl of current throug the wires 82,- 82, andy thus causes light from the lamp 87 to under o variations in intensity, these variations eing analogous to the 80 changes produced atthe transmitting station.' by the action of the light from the image upon the selenium cell 17. Following the particular instances -of the light spot, as above described, We will see .that the light of the lamp 87 becomes momentarily brighter at the instant when the alternating current impulse is sent over the line 47. The

,fact that the line ,has a condenser 79 is immaterial, for the reason that alternating cur- 90 rent impulses vcan readily be sent through a condenser. .The lamp 87 thus giving a certain flush of light at the particular instant when the slots 91 and 105 occupy the proper relative kspatial relation a light spot is roduced momentarily upon the screen 109. he rotation of the movable parts following the cycle of operations just described causes the spot in question to be reproduced again and again with such great rapidity that'its a pearance to the eye is continuous. If tge existence of the light spot yupon the screen 109 is not in fact continuous this is compensated by the natural phenomenon known as the persistency of vision. Having explained how a spot of light is transmitted and re- I pr'oduced, it is easy to see that a black spot or a part not illuminated in the image to be transmitted will produce upon the screen 109 a dark spot of the same shade. It is also 110 easy to see that the entire image to be transmitted may be considered as made up of spots or squares several hundred to the inch measured in either direction, and consequently the image when reproduced may have as much action and delicacy in tone as is the case with a so-called half-tone engraving or photograph. It will also be seen that thev relative size of the image reproduced may be controlled altogether by focusing the objectives or lenses. p While the lamp 48, the revoluble cylinder 54 and related parts constitute a type of switch which is controllable by light, I do not limit myself to this kind of switch. The 125 apparatus shown at the right of Fig. 2 is essentially a switch and I mostly prefer the switch controllable by light, for the reason that its movements can readily be made suficiently rapid without undue Wear. Neither do I limit myself to the particular arrange- I ment of any of the other parts shown either at the receiving station or at transmitting station. .l

,. I do not limit myself to the use of any particular part shown at either the transmitting station or the receiving station, nor to any particular form of conductor for connecting the stations. Neither do I limit myself, to the use of a condenser in the main line.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination of a light-controlled cell, a belt movable relatively thereto and provided with a slot, means for defnin an lmage upon said belt and upon s0 muc of said cell as is left exposed by said slot, a lightcontrolled switch for shiftinnr an electric current to different parts of said li lit-controlled cell for the purpose of enab 'ng the light passing through said slot to said cell to roduce variations in said electric current, a ine Wire energized by said variations of said current, and mechanism controllable b s aid currents passing through said line wire for the purpose of reproducing at a dist'ance an image simulating that thrown upon said belt and said light-controlled cell.

2. The combination of a line Wire, means for impressing thereupon electric impulses analogous to variations in the light of an image, an electric lam controllable by variations of current in said line Wire, a movable belt disposed adjacent to said lampand provided with a slot, a movable wheel disposed adjacent to said lamp and rovided with a slot crossing said slot in sai belt, means for moving said belt and said wheel in planes tion, a light-controlled cell and a light-con-V trolled switch disposed at said transmitting station and connected with the synchronizing motor at said transmitting station, a line connected with said li lit-controlled cell and with said light-control ed switch for conveying to a distance electric impulses roduced i by the conjoint action of said wht-controlled switch and said light-contro ed cell,

and mechanism connected with said synchronizin motbr at said receiving station for re ro ucing an image.

4. 'llhe combination of a line wire,l means forl energizing the same by electric currents, the intensity of said currents re resenti the relation between lights and sliadows o an image to be transmitted, a vacuum tube located at the receivin station and adapted to be energized by said currents from said main line, and means for energizing said vacuum tube to a predetermined normal extent independently of said currents from said main line.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

SIDNEY ROTHSCHILD. 

